(ii) 36 Palxontologia Sinica Ser. B. 



The endoconch is of large size, ovately elliptical in section, and nearly marginal to the 

 outer shell (being 0.7 mm. distant from the ventral side). It measures 8 mm. in the 

 longer diameter and 6 mm. in the shorter at the upper end of the fragment, where the 

 actual diameter of the ectoconch can not be determined, but the ectoseptal distance is 

 about 7 mm. This fragment is 123 mm. in length. At the lower part of the specimen, 

 the ectotheca as well as the ectosepta have been crushed, and the endoconch remains 

 protruding with some invaginated tubi preserved on its sides. Rate of increase 1:17. 



In both of the specimens the camene are lined with the organic stereoplasm in 

 moderate thickness, but some are perfectly empty. Test unknown. 



Comparison: In its general form, this species may be compared with Endoceras dis- 

 iansHalV. But our shell has a much smaller endoconch and an ovately elliptical section of 

 the ectoconch, which is quite different from that of Hall's species. It is also distinguished 

 from Vaginoceras wahlenbergi and V uginoceras endocylindricum by its more distant 

 ectosepta, ovately elliptical section of endoconch and less rapid tapering of the ectoconch. 



Horizon and Localities: One specimen (PI. V., Fig. i) was obtained from the 

 bed just above the massive blue limestone at the western end of Pei-yang-shan, and 

 the other (PI. V., Fig. 2) from the same horizon at He-chiao, Chung-yang-hsien. (Coll. 

 C. Li and W. P. Shu.) 



Vaginoceras (Endoceras) belemnitiforme Holm 



Plate I., Fig. 8 



1885. Endoceras belemnitiforms Holm: Palfeontologische Abhandlungen, Bd. HI, Heft I, p. 5, Taf. 

 I, figs. 1-3. 



Shell cylindrical, straight, embedded in the upper red Tafang hmestone 

 and without any trace of the test remaining. It tapers at the rate of about i in 

 10. The apical portion has not been observed, and the larger extremity is also incom- 

 plete. The ectoconch is subcircular (probably by compression) in transverse section 

 with an endoconch lying at its margin. 



The ectosepta are widely separated from each other, the distance equalling 

 nearly half the diameter of the outer shell. In actual measurement it reaches 12 mm. 

 at the diameter of 24 mm. When the ectoconch enlarges to 26 mm. in diameter, 

 it is reduced to, 10 mm. After that it assumes the original length again. Though the 

 distances between septa vary slightly, on the whole they are fairly constant 



I. Hall: Palfeontology of New York, Vol. I, p. 220, pi. LVIII, figs, i a,b. 



